This invention relates generally to a method and apparatus for charging rechargeable batteries.
The battery packs for portable power tools, outdoor tools, and certain kitchen and domestic appliances may include rechargeable batteries, such as lithium, nickel cadmium and lead-acid batteries, so that they can be recharged rather than be replaced. Thereby a substantial cost saving is achieved. Some users of battery energized equipment may have need for batteries having substantially different capacities, and to properly charge batteries, different charging rates should be used to avoid damaging the batteries.
A substantial cost and space saving is realized by providing a universal charging apparatus for charging the different batteries which require different charging rates. Further, it would be advantageous for the charging apparatus to optimize the different charging rates for each battery, in order to avoid overcharging of the battery and/or minimize the charging time. In addition, it would be advantageous if the charging apparatus was adaptable to charge future battery technologies for which it may not have been programmed to charge.
In accordance with the present invention, a method for charging a rechargeable battery pack is proposed. The charging method comprises identifying battery capacity, determining sampling interval length according to the battery capacity, and implementing the determined sampling interval length.
Also disclosed herein is a method for charging batteries comprising identifying battery capacity, determining current-on period length in duty cycle according to the battery capacity, and implementing the determined current-on period length.
Further, disclosed herein is a battery charging apparatus comprising a charger for charging first and second batteries, where the first battery comprises a microprocessor. The charger further comprises at least one terminal for receiving a battery identification signal, so that the charger can distinguish between the first and second batteries.
Also disclosed herein is a battery/charger combination comprising a battery comprising first, second and third terminals, at least one cell disposed between the first and second terminals and a microprocessor disposed within the battery between the first and third terminals, a charger connected to the battery via the first, second and third terminals, wherein the microprocessor controls charging of the battery by sending instructions to the charger.
Additional features and benefits of the present invention are described, and will be apparent from, the accompanying drawings and the detailed description below.